package com.mashibing.juc.c_019;

import java.util.concurrent.CountDownLatch;

/**
 * @author: Yuanzt
 * @Date: 2021/3/26
 */
public class T06_TestCountDownLatch {

    public static void main(String[] args) {
        usingCountLatch();
        usingJoin();
    }
    private static void usingCountLatch(){
        Thread[] threads = new Thread[100];
        CountDownLatch latch = new CountDownLatch(threads.length);
        for (int i = 0; i < threads.length; i++) {
            threads[i] = new Thread(()->{
               int result = 0;
                for (int j = 0; j < 10000; j++) result += j;
                latch.countDown();//本身就是原子性的，没有线程安全问题
            });
        }

        for (int i = 0; i < threads.length; i++) {
            threads[i].start();
        }
        try {
            latch.await();//阻塞等待线程结束
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("end latch");
    }

    private static void usingJoin(){
        Thread[] threads = new Thread[100];
        for (int i = 0; i < threads.length; i++) {
            threads[i] = new Thread(()->{
                int result = 0;
                for (int j = 0; j < 10000; j++) result += j;
            });
        }
        for (int i = 0; i < threads.length; i++) {
            threads[i].start();
        }
        for (int i = 0; i < threads.length; i++) {
            try {
                threads[i].join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("end join");
    }

}
